diff --git a/security/authgraph/aidl/vts/functional/Android.bp b/security/authgraph/aidl/vts/functional/Android.bp
new file mode 100644
index 0000000..fc13759
--- /dev/null
+++ b/security/authgraph/aidl/vts/functional/Android.bp
@@ -0,0 +1,48 @@
+//
+// Copyright (C) 2023 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+package {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "hardware_interfaces_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["hardware_interfaces_license"],
+}
+
+cc_test {
+    name: "VtsAidlAuthGraphSessionTest",
+    defaults: [
+        "VtsHalTargetTestDefaults",
+        "authgraph_use_latest_hal_aidl_ndk_static",
+        "use_libaidlvintf_gtest_helper_static",
+    ],
+    cflags: [
+        "-Wall",
+        "-Wextra",
+    ],
+    srcs: [
+        "AuthGraphSessionTest.cpp",
+    ],
+    shared_libs: [
+        "libbinder_ndk",
+        "libcrypto",
+    ],
+    test_suites: [
+        "general-tests",
+        "vts",
+    ],
+}
diff --git a/security/authgraph/aidl/vts/functional/AuthGraphSessionTest.cpp b/security/authgraph/aidl/vts/functional/AuthGraphSessionTest.cpp
new file mode 100644
index 0000000..cab8074
--- /dev/null
+++ b/security/authgraph/aidl/vts/functional/AuthGraphSessionTest.cpp
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#define LOG_TAG "authgraph_session_test"
+#include <android-base/logging.h>
+
+#include <aidl/Gtest.h>
+#include <aidl/Vintf.h>
+#include <aidl/android/hardware/security/authgraph/Error.h>
+#include <aidl/android/hardware/security/authgraph/IAuthGraphKeyExchange.h>
+#include <android/binder_manager.h>
+#include <binder/ProcessState.h>
+#include <gtest/gtest.h>
+#include <vector>
+
+namespace aidl::android::hardware::security::authgraph::test {
+using ::aidl::android::hardware::security::authgraph::Error;
+
+namespace {
+
+// Check that the signature in the encoded COSE_Sign1 data is correct, and that the payload matches.
+// TODO: maybe drop separate payload, and extract it from cose_sign1.payload (and return it).
+void CheckSignature(std::vector<uint8_t>& /*pub_cose_key*/, std::vector<uint8_t>& /*payload*/,
+                    std::vector<uint8_t>& /*cose_sign1*/) {
+    // TODO: implement me
+}
+
+void CheckSignature(std::vector<uint8_t>& pub_cose_key, std::vector<uint8_t>& payload,
+                    SessionIdSignature& signature) {
+    return CheckSignature(pub_cose_key, payload, signature.signature);
+}
+
+std::vector<uint8_t> SigningKeyFromIdentity(const Identity& identity) {
+    // TODO: This is a CBOR-encoded `Identity` which currently happens to be a COSE_Key with the
+    // pubkey This will change in future.
+    return identity.identity;
+}
+
+}  // namespace
+
+class AuthGraphSessionTest : public ::testing::TestWithParam<std::string> {
+  public:
+    enum ErrorType { AIDL_ERROR, BINDER_ERROR };
+
+    union ErrorValue {
+        Error aidl_error;
+        int32_t binder_error;
+    };
+
+    struct ReturnedError {
+        ErrorType err_type;
+        ErrorValue err_val;
+
+        friend bool operator==(const ReturnedError& lhs, const ReturnedError& rhs) {
+            return lhs.err_type == rhs.err_type;
+            switch (lhs.err_type) {
+                case ErrorType::AIDL_ERROR:
+                    return lhs.err_val.aidl_error == rhs.err_val.aidl_error;
+                case ErrorType::BINDER_ERROR:
+                    return lhs.err_val.binder_error == rhs.err_val.binder_error;
+            }
+        }
+    };
+
+    const ReturnedError OK = {.err_type = ErrorType::AIDL_ERROR, .err_val.aidl_error = Error::OK};
+
+    ReturnedError GetReturnError(const ::ndk::ScopedAStatus& result) {
+        if (result.isOk()) {
+            return OK;
+        }
+        int32_t exception_code = result.getExceptionCode();
+        int32_t error_code = result.getServiceSpecificError();
+        if (exception_code == EX_SERVICE_SPECIFIC && error_code != 0) {
+            ReturnedError re = {.err_type = ErrorType::AIDL_ERROR,
+                                .err_val.aidl_error = static_cast<Error>(error_code)};
+            return re;
+        }
+        ReturnedError re = {.err_type = ErrorType::BINDER_ERROR,
+                            .err_val.binder_error = exception_code};
+        return re;
+    }
+
+    // Build the parameters for the VTS test by enumerating the available HAL instances
+    static std::vector<std::string> build_params() {
+        auto params = ::android::getAidlHalInstanceNames(IAuthGraphKeyExchange::descriptor);
+        return params;
+    }
+
+    void SetUp() override {
+        ASSERT_TRUE(AServiceManager_isDeclared(GetParam().c_str()))
+                << "No instance declared for " << GetParam();
+        ::ndk::SpAIBinder binder(AServiceManager_waitForService(GetParam().c_str()));
+        authNode_ = IAuthGraphKeyExchange::fromBinder(binder);
+        ASSERT_NE(authNode_, nullptr) << "Failed to get Binder reference for " << GetParam();
+    }
+
+    void TearDown() override {}
+
+  protected:
+    std::shared_ptr<IAuthGraphKeyExchange> authNode_;
+};
+
+TEST_P(AuthGraphSessionTest, Mainline) {
+    std::shared_ptr<IAuthGraphKeyExchange> source = authNode_;
+    std::shared_ptr<IAuthGraphKeyExchange> sink = authNode_;
+
+    // Step 1: create an ephemeral ECDH key at the source.
+    SessionInitiationInfo source_init_info;
+    ASSERT_EQ(OK, GetReturnError(source->create(&source_init_info)));
+    ASSERT_TRUE(source_init_info.key.pubKey.has_value());
+    ASSERT_TRUE(source_init_info.key.arcFromPBK.has_value());
+
+    // Step 2: pass the source's ECDH public key and other session info to the sink.
+    KeInitResult init_result;
+    ASSERT_EQ(OK, GetReturnError(sink->init(source_init_info.key.pubKey.value(),
+                                            source_init_info.identity, source_init_info.nonce,
+                                            source_init_info.version, &init_result)));
+    SessionInitiationInfo sink_init_info = init_result.sessionInitiationInfo;
+    ASSERT_TRUE(sink_init_info.key.pubKey.has_value());
+    // The sink_init_info.arcFromPBK need not be populated, as the ephemeral key agreement
+    // key is no longer needed.
+
+    SessionInfo sink_info = init_result.sessionInfo;
+    ASSERT_EQ((int)sink_info.sharedKeys.size(), 2) << "Expect two symmetric keys from init()";
+    ASSERT_GT((int)sink_info.sessionId.size(), 0) << "Expect non-empty session ID from sink";
+    std::vector<uint8_t> sink_signing_key = SigningKeyFromIdentity(sink_init_info.identity);
+    CheckSignature(sink_signing_key, sink_info.sessionId, sink_info.signature);
+
+    // Step 3: pass the sink's ECDH public key and other session info to the source, so it can
+    // calculate the same pair of symmetric keys.
+    SessionInfo source_info;
+    ASSERT_EQ(OK, GetReturnError(source->finish(sink_init_info.key.pubKey.value(),
+                                                sink_init_info.identity, sink_info.signature,
+                                                sink_init_info.nonce, sink_init_info.version,
+                                                source_init_info.key, &source_info)));
+    ASSERT_EQ((int)source_info.sharedKeys.size(), 2) << "Expect two symmetric keys from finsh()";
+    ASSERT_GT((int)source_info.sessionId.size(), 0) << "Expect non-empty session ID from source";
+    std::vector<uint8_t> source_signing_key = SigningKeyFromIdentity(source_init_info.identity);
+    CheckSignature(source_signing_key, source_info.sessionId, source_info.signature);
+
+    // Both ends should agree on the session ID.
+    ASSERT_EQ(source_info.sessionId, sink_info.sessionId);
+
+    // Step 4: pass the source's session ID info back to the sink, so it can check it and
+    // update the symmetric keys so they're marked as authentication complete.
+    std::array<Arc, 2> auth_complete_result;
+    ASSERT_EQ(OK, GetReturnError(sink->authenticationComplete(
+                          source_info.signature, sink_info.sharedKeys, &auth_complete_result)));
+    ASSERT_EQ((int)auth_complete_result.size(), 2)
+            << "Expect two symmetric keys from authComplete()";
+    sink_info.sharedKeys = auth_complete_result;
+
+    // At this point the sink and source have agreed on the same pair of symmetric keys,
+    // encoded as `sink_info.sharedKeys` and `source_info.sharedKeys`.
+}
+
+TEST_P(AuthGraphSessionTest, FreshNonces) {
+    std::shared_ptr<IAuthGraphKeyExchange> source = authNode_;
+    std::shared_ptr<IAuthGraphKeyExchange> sink = authNode_;
+
+    SessionInitiationInfo source_init_info1;
+    ASSERT_EQ(OK, GetReturnError(source->create(&source_init_info1)));
+    SessionInitiationInfo source_init_info2;
+    ASSERT_EQ(OK, GetReturnError(source->create(&source_init_info2)));
+
+    // Two calls to create() should result in the same identity but different nonce values.
+    ASSERT_EQ(source_init_info1.identity, source_init_info2.identity);
+    ASSERT_NE(source_init_info1.nonce, source_init_info2.nonce);
+    ASSERT_NE(source_init_info1.key.pubKey, source_init_info2.key.pubKey);
+    ASSERT_NE(source_init_info1.key.arcFromPBK, source_init_info2.key.arcFromPBK);
+
+    KeInitResult init_result1;
+    ASSERT_EQ(OK, GetReturnError(sink->init(source_init_info1.key.pubKey.value(),
+                                            source_init_info1.identity, source_init_info1.nonce,
+                                            source_init_info1.version, &init_result1)));
+    KeInitResult init_result2;
+    ASSERT_EQ(OK, GetReturnError(sink->init(source_init_info2.key.pubKey.value(),
+                                            source_init_info2.identity, source_init_info2.nonce,
+                                            source_init_info2.version, &init_result2)));
+
+    // Two calls to init() should result in the same identity buf different nonces and session IDs.
+    ASSERT_EQ(init_result1.sessionInitiationInfo.identity,
+              init_result2.sessionInitiationInfo.identity);
+    ASSERT_NE(init_result1.sessionInitiationInfo.nonce, init_result2.sessionInitiationInfo.nonce);
+    ASSERT_NE(init_result1.sessionInfo.sessionId, init_result2.sessionInfo.sessionId);
+}
+
+INSTANTIATE_TEST_SUITE_P(PerInstance, AuthGraphSessionTest,
+                         testing::ValuesIn(AuthGraphSessionTest::build_params()),
+                         ::android::PrintInstanceNameToString);
+GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(AuthGraphSessionTest);
+
+}  // namespace aidl::android::hardware::security::authgraph::test
+
+int main(int argc, char** argv) {
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}